Dolly's creator to attempt creating cloned mouse

Tuesday, 07 December 2004, 20:30 IST
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EDINBURGH: Dolly the Sheep, the first mammal to be cloned from an adult cell, died last year due to premature aging, but its creator believes he can create a perfect cloned animal by switching off a "biological clock" present in the nucleus of the cell. Ian Wilmut of the Roslin Institute near Edinburgh, who had created Dolly in 1996, said he had discovered that a biological clock embedded in the nuclei of cells turned biological processes on and off and even instructed a cell when to die, reported the Scotsman newspaper. The crucial step, according to him, was to figure out how to flick the many biological switches in the nucleus and convince them that they were in a very young organism. Wilmut said that it was a difficult problem, adding that he was confident he could crack it given a decade. But this time around, the creature would probably be a mouse, he said. Said Wilmut: "If you look at the organisation of chromosomes in cells, you will find that the chromosomes in the nucleus of an adult have a particular kind of organisation (whereas) the early embryo has nuclei organised in slightly different ways. "We need to learn how to help the oocyte change the organisation of the nucleus. We need to identify the molecules that can do that and give them more access to make those changes." According to Wilmut, a nucleus transferred to an egg cell (oocyte) while cloning acted as if they were the same age as the organism they came from. In the case of Dolly, whose genetic material was taken from an ewe, the clock effect caused her arthritis and lung cancer, causing her to die at six, when the average life span for a sheep is 10 to 16 years. The scientist claimed to have turned down many lucrative offers at other research institutes, and decided to stay on in Roslin to continue his work in bio-research.
Source: IANS
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